Oliver Stoner, Руководство по эксплуатации

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III. HOW DOES A STONER WORK?
All gravity separators and stoners utilize the same principles to effect a separation. Once these principles are
understood, it is usually a simple step to adjust a stoner to produce an optimum separation. About 250 B.C.,
Archimedes discovered the law of specific gravity, which is "ALL BODlES FLOATlNG IN OR SUBMERGED IN
A LlQUlD ARE BUOYED UP BY A FORCE EXACTLY EQUAL TO THE WElGHT OF THE LlQUlD THEY DIS-
PLACE." The specific gravity of a particle is the ratio of its density to some standard substance, the standard
usually being water with a unit of 1. Particles having a specific gravity of less than 1 will float and particles
with a specific gravity greater than 1 will sink.
Oliver stoners use air as a standard rather than water. Since air is lighter than water, the relative difference
between particles of differing weights is widened. For this reason, the stoner is a very, sensitive machine and,
when operated correctly, can produce a very precise separation.
THE PROCESS OF STRATlFlCATlON
Air is used as the separating medium for the process of stratification. Stratification occurs by forcing air
through the particle mixture so that the particles rise or fall by their relative weight to the air. Figure 1 below
represents a cross section of the stoner directly over a fan. A particle mixture has been introduced on top of
the screen deck with the fans off.
In Figure 2 the fan has been turned on so that the heaviest particles rest on the surface of the deck and the
lightest particles are completely free of the surface of the deck. Proper regulation of the air flow at this time is
critical or all particles will be blended and lifted free from the separating surface by excess air (Figure 3).
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FIGURE 1 FIGURE 2 FIGURE 3
DECK
AIR
DISTRIBUTOR
AIR GATE
DECK
AIR
DISTRIBUTOR
AIR CONTROL
GATE
DECK
AIR
DISTRIBUTOR
AIR CONTROL
GATE